Electronic devices may be provided with wireless communications capabilities. To handle wireless communications, electronic devices include communications circuitry. The communications circuitry may include antennas, transmission lines, and transceiver circuitry operating at radio frequencies. Radio-frequency circuits may be formed on substrates such as flexible printed circuits.
Challenges can arise in forming radio-frequency circuitry on flexible printed circuits. For example, some flexible printed circuit materials such as extruded liquid crystal polymers that exhibit desirable radio-frequency properties such as low dielectric constant and low loss tangent values may be fragile. If care is not taken, the use of these flexible printed circuit materials may make a radio-frequency circuit susceptible to damage, potentially reducing device reliability and lowering manufacturing yields.